Flume Tank Testing of 1:4 scale model trawl doors

Summary

This report describes a test procedure to obtain accurate performance curves of model trawl doors in a Flume Tank. The purpose is to establish a consistent method of predicting door performance in order that fishermen and others can be advised of the best size and design of door for a particular net. The performance of a single model trawl door is assessed by measuring the tensions and angles of the warp and bridle which retain the door in a fixed position in the tank. Two coefficients are derived : CL representing lift or spreading force and CD representing the drag force. CL/CD represents a measure of efficiency of the door. The Flume Tank equipment required to measure the necessary parameters is described along with the experimental procedures. Results are given for standard flat and vee doors over a range of angles of attack and heel. This data in the form of CLand CD is used as a base against which to compare the performance of other door types. This report has been produced from a scanned original and may therefore contain some formatting and other inaccuracies. In cases where this affects the technical content, a paper copy of the original report can still be obtained from Seafish.

Authors

• N. Ward,
• A. Strickland

Publication Reference No.

SR342